Can't dance, no oil painting, and now the biggest insult for John Sergeant ...

John Sergeant dancing with Kristina Rihanoff during the Live Show for the BBC programme Strictly Come Dancing. Photograph: BBC/PA

He's been called a "dancing pig" and a "ballroom chancer" whose moves are "like seeing your grandad give a turn every Saturday night", and so far John Sergeant has borne it all with irrepressible good humour and a clodhopping clack of his Cuban heels.

But yesterday the former BBC political editor, whose baby elephant moves on Strictly Come Dancing have won the adoration of the public and the frustrated irritation of the show's judges, was hit with perhaps the cruellest insult of them all.

Arlene Phillips, one of four judges on the programme, said that while his more talented peers spend hours working on their routines in the practice studio, Sergeant, 64, can be found "fooling around" - by reading the Guardian. "There is nothing correct about his performances," Phillips told BBC Breakfast News. "In terms of dance everything is wrong - posture, movement, the position of his head.

"When [other celebrities] put hours in the practice studio they are constantly working. They do not sit down, and I know with John, he sits and reads the Guardian. A lot of time he and his dance partner spend fooling around." She added: "I hope this does not go on to the final."

Sergeant is the unlikely star of the show, refusing to emulate the technique of his rivals. He is as defiantly graceless nine weeks in as he was at the beginning. But with Sunday's ejection of the actor Cherie Lunghi, a talented dancer, the bubbling irritation of the judges has become more marked. The losing contestant is chosen by the judges from the two bottom-ranked couples - a position Sergeant has avoided because of his public popularity.

Lord Mandelson became the latest to reveal himself as a fan of the Sergeant shuffle, saying: "I was cheering for John Sergeant on Saturday with, I have to say, a degree of envy. Another day, invite me back and I will show you what I can do." The programme's producers said they would bear him in mind.

So far, the prime minister has yet to comment publicly. He and his wife, Sarah, are known to prefer X Factor.